The research program of this laboratory centers of the isolation, properties and biological functions of proteins associated with DNA in the chromosomes of higher organisms. Particular emphasis is placed on reactions which modify the structures of histones and other nuclear proteins after their synthesis is completed. Reactions such as acetylation of lysine residues, methylation of lysine and arginine residues, and phosphorylation of serine and threonine residues in the intact polypeptide chains of nucleic acid binding proteins are beleived to play an important role in the control of chromatin structure and transcriptional activity. The chemical and enzymatic basis of these reactions, and their consequences in terms of DNA conformational changes and template function, are major topics of investigation.